Kienberg (Middle Miocene, upper Badenian) represents one of the richest and most significant paleontological localities of the marine Miocene in the Czech Republic. Despite the fact that Kienberg has been known since the 19^th century and provided remains of hundreds of taxa, recently it became a rather overlooked locality. Therefore, we provide a current overview of geological and paleontological research at the locality. Fossil marine invertebrates are the most common, and the vertebrate fossil record is represented mainly by bony fishes, sharks, and rays. Rare remains of a crocodylian and a sea turtle are newly identified. A tooth of Crocodylia indet. and a proximal fragment of a left femur of Pan-Cheloniidae indet. are described and compared within spatiotemporally co-occurring forms. The presence of a sea turtle fits well within the context of the strict marine fauna documented from Kienberg, whereas the crocodylian tooth in the marine section could imply a saltwater tolerant crocodylian species or a transport of this only crocodylian remain from more distant brackish/freshwater environment.